We hung CDs from the ceiling in our computer lab with fishing line. It was easy to do, decorative and I was told it also helps to deflect sound waves from the computers. We used all those freebie CDs you get in the mail and now even in cereal boxes (Honey Nut Cheerios).
Moderator adds some photos found over in the Computer Workshop Photo forum from St. Thomas Presbyterian's Computer Lab in Houston TX, CDs are hung in front of the window.